The 90 wins by the Diamondbacks and Rockies were the fewest to lead the NL since 1959, with the exception of the strike-shortened seasons of 1981, 1994 and 1995. No NL team won or lost 95 games for the first time since 1983.

Also, this was the second consecutive season in which no team won at least 60% of its games, the first time that this has happened in Major League Baseball history.

Barry Bonds, left fielder for the San Francisco Giants, surpassed Hank Aaron as the all-time home run leader in Major League Baseball history with his 756th career home run off Mike Bacsik of the Washington Nationals in the fifth inning of their game August 7 at AT&T Park in San Francisco, California. The 3–2 pitch with one out and nobody on base was hit at 8:51 PM US PDT and according to hittrackeronline.com was estimated to have gone 422 feet. However, the Nationals came back and won the game, 8–6. Through his final home game (and last game of the season) on September 26, Bonds has hit 762 home runs. Five days earlier, the Giants announced that Bonds would not be back in San Francisco for the 2008 season, thus ending a relationship of fourteen seasons.

As for the baseball that was hit for the record, Queens, New York resident and Mets fan Matt Murphy, 22, who survived a near riot while en route to Australia and stopped over to watch the game on a lark, put the ball up for auction online. The winning bidder was fashion designer Marc Ecko, who purchased the baseball for $752,467 (US), and then let fans decide what to do with it in an internet poll by either outright donating the ball to the Baseball Hall of Fame unbranded, donating it with an asterisk attached as many people believe Bonds used performance enhancing drugs (including steroids) to further break the record, or have the baseball sent into outer space. The vote decided that an asterisk would be added, and the ball donated to Cooperstown. In an interview that aired on MSNBC's Countdown with Keith Olbermann on November 1 and 2, Bonds stated to interviewer Jim Gray that if the ball were to be put on display with the asterisk, he would boycott his own Hall of Fame induction if he were elected.

Ryan Howard, first baseman for the Philadelphia Phillies, hit his 100th career home run on June 27 against the Cincinnati Reds at Citizens Bank Park in Philadelphia, Pennsylvania. He accomplished this in his 325th career game, becoming the fastest player in Major League Baseball history to reach this milestone. Howard also set a dubious record September 27, when he struck out against the Braves' John Smoltz, whiffing for the 196th time in a season. He ended the season with 199 strikeouts, a new record.

Craig Biggio, second baseman for the Houston Astros, got his 3,000th career hit on June 28 against the Colorado Rockies at Minute Maid Park in Houston, Texas. Biggio was 5-for-6 in the game and was thrown out at second on his 3000th hit. Biggio became the 27th member of the 3000 hit club, and is one of only nine players to get all 3,000 hits with one team. Biggio announced later in the season that he would retire following the completion of the season, finishing his career with 3,060 hits.

Alex Rodriguez, third baseman for the New York Yankees, hit his 500th career home run on August 4 against the Kansas City Royals at Yankee Stadium. At 32 years, 8 days of age, he became the youngest player to reach the 500-homer mark.

Left-handed pitcher Tom Glavine of the New York Mets, earned his 300th career win against the Chicago Cubs at Wrigley Field on August 5 in front of a nationwide audience on ESPN's Sunday Night Baseball. Glavine became the fifth left-handed pitcher to win 300 games, the first since Steve Carlton in 1983, and the 23rd pitcher to win 300.

Greg Maddux of the San Diego Padres became the first pitcher in history to record at least 10 wins in 20 consecutive seasons in the Padres' 14–3 defeat of the Phillies at Citizens Bank Park in Philadelphia, Pennsylvania on August 24. The game also marked Maddux's 700th career start.

Chicago White Sox designated hitter Jim Thome hit a two run walk-off home run on September 16 for his 500th career home run at U.S. Cellular Field in Chicago, leading the White Sox to a 9–7 win over the Los Angeles Angels, making the 2007 season the first in which three players hit their 500th homer. It was also the first time in MLB history that a player reached the 500-homer mark with a walk-off homer.

The Chicago Cubs of the National League recorded their 10,000th win in all major leagues against the Atlanta Braves on June 3, at Wrigley Field in Chicago. They became the second team to reach this mark after the New York/San Francisco Giants were the first. However, this tally includes 77 wins gained during Chicago's years in the National Association (1871, 1874 and 1875). These wins are not considered official by Major League Baseball. Through 2007, the Cubs have 9,985 official wins.

The Philadelphia Phillies of the National League, recorded their 10,000th loss, a 10–2 loss to the St. Louis Cardinals on July 15, at Citizens Bank Park in Philadelphia, Pennsylvania. They became the first team in the four major sports leagues (MLB, NHL, NFL, and NBA) to accomplish this. However, Major League Baseball's season, by number of games, is almost twice as long as the NHL and NBA seasons and ten times longer than the NFL season. Also, the Phillies have existed since 1883, more than 30 years longer than any of the other major North American leagues (NHL: 1917, NFL: 1920, NBA: 1946).

The Texas Rangers of the American League scored 30 runs in a 30–3 rout of the Baltimore Orioles on August 22, at Oriole Park at Camden Yards in Baltimore, Maryland. The Rangers set both a new American League and the modern Major League (post-1900) record for runs scored in a game, and became the first team since the Chicago Colts scored 36 runs against the Louisville Colonels in 1897 to score at least 30 runs in a game. The previous record was 29, first set by the Boston Red Sox in 1950 at Fenway Park against the Orioles' predecessors, the St. Louis Browns, and equaled at Municipal Stadium in Kansas City, Missouri in 1955 by the Chicago White Sox against the Kansas City Athletics, who had moved from Philadelphia the year before. The Rangers won the nightcap, 9–7 and extended the newly-set record for most runs in a doubleheader in the American League to 39.

The New York Mets became the first team in the divisional era (since 1969) to blow a seven game lead past September 12 as the Philadelphia Phillies raced by them on September 30 to win the National League Eastern Division at Citizens Bank Park in Philadelphia, Pennsylvania, defeating the Washington Nationals, 6–1, while the Mets fell to the Florida Marlins, 8–1 at Shea Stadium in Flushing Meadows, Queens, New York.

The Colorado Rockies, winners of the NL wild-card, won their first-ever playoff series by sweeping the Philadelphia Phillies in the NLDS. The Rockies then swept the Arizona Diamondbacks in the NLCS to claim their first-ever National League championship.

Three no-hitters were pitched during the 2007 regular season. This is the most in a single season since the three pitched in 2001. All three no-hitters in 2007 were in the American League, which is the most in a single league since the record-tying 1991 season when the two leagues combined for seven no-hitters (4 AL, 3 NL).

Clay Buchholz, a rookie pitcher for the Boston Red Sox, pitched a no-hitter on September 1 against the Baltimore Orioles at Fenway Park in Boston, Massachusetts during his second career Major League appearance.[3] It was the 17th no-hitter in Boston Red Sox history, and the first Boston rookie to throw one. He became only the second player to throw one in his second career game. On the day the rosters expanded, Buchholz was recalled from Triple-A to start the game because Tim Wakefield was scratched due to a bad back. Buchholz improved to 2–0 for his career. Ironically, in his pre-game interview, manager Terry Francona had said "Even if he throws a no-hitter he's still going back to the minors."[citation needed] Buchholz remained on the active roster for the rest of the regular season.

Plácido Polanco, a second baseman for the Detroit Tigers, set a new Major League record by playing in his 144th consecutive errorless game on August 13, in a 7–2 loss to the Oakland Athletics. Polanco appeared to have his streak snapped at 147 games when he was charged with an error in the first inning of the August 24 game vs. the New York Yankees.[5] However, the next day, after conferring with the umpiring crew, the official scorer determined the error was instead charged to first baseman Marcus Thames.[6] This extended the streak to 149 games. Polanco also broke the record for consecutive chances without an error by a second baseman July 31. He passed Luis Castillo's mark of 647. Polanco finished the 2007 season without making an error, thereby becoming the first everyday second baseman in MLB history to play an entire season without committing an error.[7]

On April 22, Boston Red Sox players Manny Ramírez (left fielder), J.D. Drew (right fielder), Mike Lowell (third baseman) and Jason Varitek (catcher) hit four consecutive home runs in a game against the New York Yankees at Fenway Park. This marked the fifth time in Major League history that this feat was accomplished. All four home runs were hit off of Chase Wright in the 3rd inning.

Chone Figgins, third baseman for the Los Angeles Angels, went 6-for-6 on June 18 against the Houston Astros at Angel Stadium of Anaheim in Anaheim, California.[8] Figgins drove in the game-winning run on a triple in the ninth inning to win the game 10–9. He became the second player in team history to go 6-for-6; then-California Angels outfielder Garret Anderson accomplished this feat on September 27, 1996. Figgins also became the first player in Major League history to go 6-for-6 with a walk-off hit in a regulation nine-inning game.

Willie Harris, a left fielder for the Atlanta Braves, went 6-for-6 on July 21 at Turner Field as the Braves routed the St. Louis Cardinals, 14–6.[9] He hit two triples with six RBIs during the night, both career-highs. Harris became the seventh player in franchise-history to go 6-for-6 and the fourth player in Major League history since 1950 to go 6-for-6 with 6 RBIs.

Garret Anderson, a left fielder for the Los Angeles Angels, set a franchise record and became the first player since April 2005 to get 10 RBIs in a game on August 21 at Angel Stadium of Anaheim, leading the Angels to an 18–9 victory over the New York Yankees.[10] Anderson broke the Angels' franchise record for RBIs in a game, previously set by his teammate, Vladimir Guerrero, who had nine RBIs on June 2, 2004 against the Boston Red Sox. Anderson also became the first player since Alex Rodriguez to hit 10 RBIs in a game, doing so on April 26, 2005, ironically in a game against the Angels at Yankee Stadium. The 10 RBIs also was a career-high, eclipsing his previous mark of seven which he set on September 5, 2002 in an Angels' 10–1 victory over the Tampa Bay Devil Rays.

On September 9, the Milwaukee Brewers became the first team in recorded Major League history to open a game with three consecutive home runs. The three home runs were hit in order by Rickie Weeks, J.J. Hardy, and Ryan Braun at Great American Ballpark in Cincinnati. Reds pitcher Phil Dumatrait notched the loss after submitting the three home runs in only 10 pitches.[11]

Prince Fielder of the Milwaukee Brewers became the youngest player in Major League Baseball history to hit 50 home runs in a season. Prince hit his record-breaking home run at the age of 23 years, 4 months, and 18 days. His father, Cecil Fielder, hit 50 home runs in 1990 with the Tigers.

Two new members of the 20–20–20–20 club (20 doubles, 20 triples, 20 home runs and 20 stolen bases) were entered in 2007. Curtis Granderson, Detroit Tigers center fielder, was the first to join (and third overall) this exclusive group when he stole his 20th base of the 2007 season, doing so September 9. On September 30, the last scheduled day of the regular season, Philadelphia Phillies shortstop Jimmy Rollins joined Granderson as the fourth player to accomplish this feat by hitting his 20th triple of the 2007 season.

Kazuo Matsui hit his first ever grand slam and became the second person in MLB history to do so in the post-season.

Bobby Cox, manager of the Atlanta Braves was ejected from his 132nd game on August 14 against the San Francisco Giants, surpassing John McGraw of the New York Giants for the all-time record.

Trever Miller, a relief pitcher for the Houston Astros, shattered Scott Aldred's record for most appearances in a season without a win or a loss, with 76. The previous record was 48, set by Aldred in 1998 as a member of the Tampa Bay Devil Rays.

On July 10, 2007, at AT&T Park in San Francisco, the American League defeated the National League by a score of 5–4. The victory was the tenth consecutive (excluding the 2002 tie) for the AL, and their eleven-game unbeaten streak matches only the NL's streak from 1972 to 1982 in All-Star history.

On April 15, Major League Baseball celebrated the sixtieth anniversary of the debut of Jackie Robinson at Ebbets Field in Brooklyn, breaking the color barrier. Cincinnati Reds outfielder Ken Griffey, Jr. asked Robinson's widow, Rachel, and commissioner Bud Selig for permission to wear Robinson's number 42 in honor of him. He was granted permission, and Selig later said that any player who wanted to wear number 42 on his jersey could. The jersey was worn without the players' name on the back, as was the case when Robinson played with the Brooklyn Dodgers. All jerseys that were worn were auctioned off with all the proceeds donated to the Jackie Robinson Foundation, an organization which awards scholarships to African-American high school graduates to further themselves in colleges academically.

The Dodgers, Cardinals, and Brewers elected to have the entire team wear number 42 in his honor. The Pittsburgh Pirates, Phillies, and Astros were also scheduled to share that honor, but their games were postponed due to rain. The Phillies and Astros honored Robinson on April 23 when they made up their postponed game as originally planned, while the Pirates waited until April 27 to honor Robinson by wearing #42 as a team against the Reds.

On August 10, the Cleveland Indians paid tribute to Larry Doby, the first African-American to play in the American League at Jacobs Field in Cleveland, Ohio. Every player on the Indians wore number 14, the number Doby wore during his career with the Indians.

Biggio joined the 3000 hit club during the 2007 season, and became the first player to be called out in the same play that they got their 3000th hit. He was tagged out while trying to stretch his hit into a double. He announced his retirement on July 24, about a month after achieving the milestone. He finished his career with 668 doubles, good for 5th all-time at the time he retired. In the penultimate game of his career, on September 29, he was brought in as a catcher, playing the position for the first time in 15 years.

Conine, then of the New York Mets, announced his retirement on September 20, right before their last road trip to visit the Florida Marlins. The Marlins, fans of which refer to him as "Mr. Marlin", honored him for his contribution to their two World Series titles in 1997 and 2003. Ironically, losses to the Marlins contributed to the Mets failing to make the playoffs.

The Arizona Diamondbacks changed from purple, copper and turquoise to a modern Sedona Red, sand and black scheme, complete with re-colored primary and alternate logos, along with new scripts and sleeve insignia.

The Chicago Cubs have restored player names to the back of their home jerseys and removed their blue alternate jersey.

The Cincinnati Reds changed from pinstriped vests to traditional sleeve jerseys at home with scarlet soutache trim de-emphasizing black trim and a new early 20th-Century lettering and numbering font as well as the return of "Mr. Redleg", the 1950s sleeve patch/mascot supplanting the modern "Mr. Red".

The Los Angeles Angels added a red alternate jersey.

The Los Angeles Dodgers restored player names to the back of their jerseys and removed the white trim from their road uniforms.

The Pittsburgh Pirates added a red alternate jersey to be worn on Friday nights, paying tribute to the city's "Redd Up" cleanup campaign. The lone exception was the April 27 game against the Cincinnati Reds when the team wore #42 in tribute to Jackie Robinson as stated above.

The Atlanta Braves wore a patch remembering the lives of Johnny Sain and Lew Burdette, two players who were traded for each other in a deal in 1951 between the then-Boston Braves and the New York Yankees. The patch read their initials ("JS" on the left, "LB" on the right) between the number they shared, "33." Both died during the offseason.

The Minnesota Twins wore a black armband during their first home stand and a patch in memory of Herb Carneal, their radio play-by-play announcer from 1962 until 2006, who died on April 1, 2007 for their first home stand. They then switched to a red circular patch featuring an old-style microphone and the name "Herb."

The New York Yankees wore a black armband in memory of Cory Lidle, who was killed in a plane crash in Manhattan on October 11, 2006. They added the retired #10 above the armband in memory of longtime player and announcer Phil Rizzuto, who died on August 14.

The Philadelphia Phillies wore a black patch with "VUK" written in white in memory of longtime team player, coach and scout John Vukovich, who died during Spring Training.

The San Francisco Giants wore two patches for the 2007 season:

An alternate version of the 2007 All-Star Game logo; being the host team of the 2007 All-Star Game.

Following the death of former player Rod Beck, they added a black square with "BECK 47" in white lettering.

Following the death of pitcherJosh Hancock, they added a black "32" patch on their jerseys in his memory.

The Tampa Bay Devil Rays wore a patch celebrating the franchise's 10th season of existence.

The Toronto Blue Jays wore a patch in black with a white "SP" starting on August 20 in remembrance of Sam Pollock, a legendary NHL general manager most notably with the Montréal Canadiens who died on August 15. Pollack had served as the Jays' Chairman and CEO from 1995 to 2000.

The Washington Nationals wore a patch for their last home stand, commemorating the final few games at RFK Stadium.

Josh Hancock, a relief pitcher with the St. Louis Cardinals, died on April 29 in a car accident outside St. Louis, Missouri. The 29-year-old pitcher was killed within a couple of minutes after impact when the SUV he was driving crashed into a towing vehicle on Interstate 64. This marks the second time in five years that a Cardinals pitcher lost his life before a game, the other being Darryl Kile, who died suddenly on June 22, 2002. The team postponed their game scheduled for later that day against the Chicago Cubs to pay respect to Hancock.

A police report revealed that Hancock was intoxicated at the time of his fatal accident with a blood-alcohol level of 0.157, nearly double the legal limit in Missouri. Police also found 8.55 grams of marijuana along with a glass smoking pipe in his vehicle, although toxicology tests later proved no drugs were in his system except alcohol. In addition, Hancock was talking on a portable cellular telephone when the accident occurred and not wearing a seatbelt. An accident reconstruction team determined that Hancock was driving 68 mph in a 55 mph zone.[12]